The present application relates to a lens mechanism having polymer actuator elements and an imaging device having the same.
Recent years have seen remarkable advances of portable electronic devices including personal computers and PDAs in terms of performance. Commonly, such devices offer imaging capability thanks to a lens mechanism which incorporates a lens unit. In such devices, the lens unit of the lens mechanism moves along the optical axis as a movable section to achieve focusing and zooming.
Voice coil motor and stepping motor have been popular for use as a drive section to move the lens unit. Recently, however, lens mechanisms have come along which use a polymer actuator element as a drive section for more compact size (refer, for example, to Japanese Patent Laid-Open No. 2006-293007 (Patent Document 1, hereinafter) and Japanese Patent Laid-Open No. 2007-151221 (Patent Document 2, hereinafter)). A polymer actuator element includes, for example, an ion exchange resin sandwiched between a pair of electrodes. Such a polymer actuator element is displaced in a direction orthogonal to the surface of the ion exchange resin film as a result of the development of a potential difference between the pair of electrodes.